The Rainbow Daytona is one of the most mysterious and obsessed-over watches in the Rolex catalog, or rather, just outside it. It is built on the same case, the same caliber, and the same bracelet design as a production Daytona. It is also covered in 92 gemstones, trades at multiples of retail, and has never once appeared in a Rolex advertisement. That combination of sports-watch bones and haute joaillerie execution is what makes it genuinely interesting in the modern Rolex market.